Method of producing colored light-rays.



P. G. HEWITT. METHOD OF PRODUCING COLORED LIGHT RAYS.

ww W .H m Ma MW PETER cooPER HEWITT, on NEW YORK, N.-Y., ASSIGNOR, BY- MESNE, ASSIGNMENTS, To I cooPER HEWITT ELEoTRIo COMPANY, A CORPORATION OF NEW YORK.

METHOD or rnonuomo conoREn LIGHT-RAYS.

Specification of Letters Patent.

Patented Dec. 22, 1908.

Application filed April 8, 1901. Serial No. 54,179.

' resident of New York, in the county of New the original source of light.

York and State of New York, have invented certain new and useful Improvements in Methods of Producing Colored Light-Rays, of which the following is a specification.

The present invention relates to means for combining with the rays of a source of light which is deficient in some desired ortion of the spectrum other rays produce by the transformation of certain of the waves of the defective source into luminous waves of such a character as to supply the defects of p I am aware ,that it is known amon those skilled in the art that certain materia S have the property of transforming energy of certain wave lengths into energy of other wave lengths, and 1 do not claim broadly to have discovered this quality. Certain of such materials have been recognized and called fluorescent materials. i

It is, however, the object of my invention to make use of this property of such bodies to render useful a source of energy which is deficient in certain wave lengths and more particularly with respect to certain sources of illumination which are defective in certain colors, correcting this diificulty and rendering them useful. It is found in many cases that a comparatively small addition of energy from the original source is sufiicient to efi'ect the desired result. I propose to gain this addition of the desired wave lengths by subjecting a portion of the energy from the original source to the action of such suitable substances in a manner that the wave lengths emitted from the material shall be an intense illumination by passing electric some of the rays derive current through the vapor 'and may then supply the ,red rays which are naturally lacking in a source of light thus created by the action of materials ada ted to transform from this source intosueh wave lengths as are adapted to give to thelight as awhole the lacking ualities so as to produce alight in who the natural defects of the original source of light do not appear.

As illustrative of this invention, the light produced by the action of electric currents on the vapor of mercury as described for instance in certain patents issued to me September 17, 1901, produced a light which is deficient in red rays but strong in yellow and green, also blue and violet. By the use of magdala red in alcoholiesolution, both on reflection and on transmission, red rays appear in the spectrum of light created from mercury vapor. These red rays may be derived from other bands but it appears from the resulting spectrum as if the greenishye(lilow ray is the ray chiefly converted into re Eosin in alcoholic solution has the prop.-

city of bringing into existence yellow and 4 green rays from some other band. Sulfate of quinin in water Solution brings into existence blue rays. By the use of different materials any rays may be brought into existence. Thesev materials, however, must be in the proper physical condition. in order to possess thisproperty whether in solution, mixture, or in their natural state. Rhodamin-in alcoholic solution has the property of bringing out red rays in quantity from light having as its source mercury vapor,

but when in solution in water it Seems to possess this property only slightly, if at all. Where it .is to be used as a paint, it ossesses the desired uality when held by fis -glue as a binder an also by starch; but when held .by ordinary glue of commerce as a binder it seems to lose this property. In gum-'aiabic or mastic it possesses thisproperty to hardly an apprecia 1e extent. It appears as if the partlcular physical arran ement of the material itself by reason 0 its mixture with some other material causes it to have this special condition. Two or more materials which, individually, do not have the re- ,quired property, may be mixed together and such mixture may possess it.

In cases. where it is desirable to use glass ,erties, certain metallic salts --may be as the carrier, on account of its natural prgp issolved therein or mixed with it so as to produce this quality of transforming the rays of ii ht, such as the peculiar conditionin whic 1 fbone-ash" arranges itself when dissolved .in' glass; also uranium; and under certain conditions the surface of glass may be made to possess this pro erty as in the case of certain iridescent g ass. Recognition ()ff'tllu value of this property as a reflector for commercial use'for transforming one ray of light into a ray of another color and also as a screen whereby the rays of light are allowed to pass through the screen undergoing transformation in their passage "instead of screening back certain fixed rays as is the ordinary practice in shades and the mingling of the resultant rays, I believe to be new with me.

In ractice l have obtained excellent results )y placing back of a-mercury va or lamp a reflector consisting of any suita lo surface, such for instance, as tin coated with rhodamin dissolved in fish-glue; also by surrounding such a lamp wholly or'in part' by a glass vessel containing an alcoholic solution of rhodamm. Other methods of combining the transformed rays with the of rays of light of one color from a untransformed rays either by these or other paints or solutions w1ll be evident from the description. 7

It will be seen that my invention contcm-' plates, among other things, the transforming iven source into rays of light of another colbr in the same source and min ling the modified or transformed rays with the other ra s. The result of this process is a light which combines the normal and the modified or transformed rays.

To illustrate my invention, I show three figures of drawings, Figure 1 re resenting a mercury vapor lamp surrounde by a vessel containing fluorescent material, and Figs. 2 and 3 representing a similar lamp combined with suitable reflectors.

In the drawings, 1 is a mercury vapor lamp having electrodes 2 and 3, the latter of which is of mercury. The electrode 2'may be of iron or other suitable materiah I The novelty of the particular apparatus shown an inner surface of fish glue combined with. rhodamin or other suitable materiall These materials are, as before, simply noted as examples. l "g. 3 shows a similar construction, the lamp'in this mstance, however, being horizontal and the reflector so arranged as to throw the reflected and the transformed rays downward to mingle with the direct rays from the source. The back of the reflector 6 should be of such material as to reflect the light through the fluorescent material on its face, whether this be a'liquid or be of the nature ofa varnish glaze. In Fig. l'where a liquid is held in aglass container I show ameans, 7, for providing a mouth to fill and replenish the reflector which may also serve as an expansion outlet.

in a divisional ap flication, filed by me September 15,- 1908, erial Number 453,187, claims are made u on certain featuresof the invention disclose herein.

1 claim as my inventiom 1. The improvement in the art of electric lighting, which consists in generating light of high illuminating power but deficient in certain color effects recognizedby the human eye as characteristic of ordinary day light, intercepting and transforming by a suitable fluorescent medium, a 'portion of the light radiated in a direction away from the region; to be illuminated, and radiating the trans-'95 formed light toward the region to be illuminated, thereby producing in said region the combined effect of the transformed light and of the light of high illuminating power.

2L In an electric lighting apparatus, means for producing light deficient in certain desirable ravs and rich in ultra-violet rays, a reflector having a fluorescing surface, located adjacent to the light producing means, whereby the light reflected from the fluorcscing surface is mingled with the light from the source.

3. In a light giving apparatus, a mercury vapor lamp, in combination with a reflector having a fluorescing surface, the said reflector being located so as to cause the light reflected therefrom to mingle with the light from the mercury vapor lamp and be thrown upon the object to beilluminated.

t. In a lighting apparatus, a mercury I vapor lamp, a fluorescing substance located ad acent thereto, and means for etl'ectmg the mingling of the light. from the lamp with the light from the fluorescing substance.

Signed at Ncw'York, in the county of New York, and State of New York, this 1st day of April A. l). 1901.

PETER COOPER HEWITT.

Witnesses:

WM. II. CAI EL, GEORGE l-I. S'roeKemneE. 

